Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

Home > Products > Circuit Protection > Transient Voltage Suppressors (TVS) > TVS Diodes

Taiwan Semiconductor Corporation BZW04-28

Name: BZW04-28
Brand: Taiwan Semiconductor Corporation
SKU: BZW04-28
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: BZW04-28

Manufacturer:: Taiwan Semiconductor Corporation

Category:: TVS Diodes

Package:: DO-204AL, DO-41, Axial

Datasheet:: BZW04-28.pdf

Description:: TVS DIODE 28.2VWM 45.7VC DO204AL

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,975

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

BZW04-28 from Taiwan Semiconductor is a unidirectional transient voltage suppressor (TVS) diode designed for high-energy surge protection in DC power rails and signal lines. It features a 28.2 V working stand-off voltage, 31.4–34.7 V breakdown voltage at 1 mA, 45.7 V maximum clamping voltage at 8.8 A peak pulse current, and 400 W peak pulse power rating per 10/1000 μs waveform - deployed in automotive lighting control modules to safeguard microcontroller I/O against load dump transients.

For engineers reviewing the BZW04-28 datasheet, BZW04-28 pinout, BZW04-28 application, or BZW04-28 equivalent, key selection criteria include clamping voltage margin relative to protected IC's absolute maximum rating, leakage current below 1 μA at 28.2 V, thermal derating above 25°C ambient, and DO-41 package compatibility with manual or wave-solder assembly processes.

Technical Context

The BZW04-28 operates as a silicon avalanche diode, triggered when reverse voltage exceeds its specified breakdown range (31.4–34.7 V). Its low dynamic impedance ensures rapid voltage clamping during fast transients such as EFT (electrical fast transients) and ISO 7637-2 load dump pulses.

It is rated for 175°C maximum junction temperature and exhibits a 0.098%/°C temperature coefficient of V_BR, enabling predictable voltage shift across automotive-grade thermal ranges. The device meets AEC-Q101 stress test requirements when ordered with "H" suffix (e.g., BZW04-28H), though BZW04-28 itself is the standard industrial variant.

Key Specifications

Parameter	Value and Actual Design Meaning
V_WM	28.2 V - Maximum continuous reverse operating voltage before conduction begins; sets upper limit for safe DC bias in protected circuit.
V_BR @ I_T=1 mA	31.4–34.7 V - Avalanche onset threshold; defines minimum overvoltage level that initiates clamping action.
V_C @ I_PP=8.8 A	45.7 V - Clamped voltage under 10/1000 μs surge; must remain below protected IC's absolute max rating (e.g., 50 V).
P_PK	400 W - Peak pulse power handling capability; determines survivability against standardized surge waveforms like ISO 16750-2.
I_R @ V_WM	<1 μA - Reverse leakage at stand-off voltage; ensures negligible standby current draw in battery-powered systems.
T_J max	175°C - Maximum junction temperature; supports operation in under-hood automotive environments without thermal shutdown.

Pinout & Package

Package: DO-204AL (DO-41), axial leaded, epoxy-molded case with cathode band marking for unidirectional polarity. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD 201 Class 2 whisker resistance.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Low-side reference terminal	Connected to ground or low-voltage return path; establishes reference for clamping action during positive transients on cathode side.
Cathode	Protected line input	Connected to the line being protected (e.g., 24 V supply rail); conducts surge current to anode when voltage exceeds V_BR.

Key Features

Feature	Design Value
400 W surge rating (10/1000 μs)	Enables robust protection against ISO 7637-2 Pulse 5a (load dump) in 24 V automotive systems without external series impedance.
Clamping voltage ≤45.7 V at 8.8 A	Provides ≥5 V margin below typical 50 V-rated CAN transceivers or microcontroller I/O pins, reducing risk of latch-up or damage.
Leakage <1 μA at 28.2 V	Minimizes quiescent power loss in always-on circuits such as vehicle body control modules with wake-up capability.
DO-41 package with UL 94V-0 molding	Supports automated through-hole insertion and reflow/wave soldering while meeting flammability safety standards for enclosed electronics.

Applications

Automotive Lighting Control	Industrial PLC I/O Protection
Use Scenario: Protecting LED driver ICs and MOSFET gate drivers in headlamp modules subjected to load dump transients up to 60 V. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 24 V supply rail and ground, clamping surges within 1 ns response time. Use Value: Prevents catastrophic failure of high-side driver ICs by limiting rail voltage to 45.7 V during 400 W transients, preserving system uptime.	Use Scenario: Safeguarding analog input channels of programmable logic controllers exposed to inductive kickback from solenoid valves. IC Role / Device Role / Timing Role: TVS mounted at terminal block entry point, shunting energy before reaching precision ADC front-end. Use Value: Maintains measurement integrity by suppressing >1 kV transients to sub-50 V levels, avoiding ADC saturation or internal ESD diode conduction.
DC Power Supply Input Stage	ESD-Prone Communication Interface
Use Scenario: Input-stage surge suppression for 24 V DC-DC converters powering embedded sensors in factory automation equipment. IC Role / Device Role / Timing Role: Primary overvoltage clamp upstream of input filter capacitor and controller IC. Use Value: Absorbs repetitive 400 W surges without degradation, extending converter lifetime and eliminating need for redundant MOV-based protection.	Use Scenario: Secondary-level ESD protection on RS-485 transceiver VCC and DE/RE pins in building management systems. IC Role / Device Role / Timing Role: Low-leakage TVS placed adjacent to transceiver pins to handle ±8 kV contact discharge per IEC 61000-4-2. Use Value: Limits transient-induced latch-up risk with <1 μA leakage at 28.2 V, ensuring reliable bus arbitration during field maintenance events.

Automotive Lighting Control

Industrial PLC I/O Protection

Use Scenario: Protecting LED driver ICs and MOSFET gate drivers in headlamp modules subjected to load dump transients up to 60 V.

IC Role / Device Role / Timing Role: Unidirectional TVS placed between 24 V supply rail and ground, clamping surges within 1 ns response time.

Use Value: Prevents catastrophic failure of high-side driver ICs by limiting rail voltage to 45.7 V during 400 W transients, preserving system uptime.

Use Scenario: Safeguarding analog input channels of programmable logic controllers exposed to inductive kickback from solenoid valves.

IC Role / Device Role / Timing Role: TVS mounted at terminal block entry point, shunting energy before reaching precision ADC front-end.

Use Value: Maintains measurement integrity by suppressing >1 kV transients to sub-50 V levels, avoiding ADC saturation or internal ESD diode conduction.

DC Power Supply Input Stage

ESD-Prone Communication Interface

Use Scenario: Input-stage surge suppression for 24 V DC-DC converters powering embedded sensors in factory automation equipment.

IC Role / Device Role / Timing Role: Primary overvoltage clamp upstream of input filter capacitor and controller IC.

Use Value: Absorbs repetitive 400 W surges without degradation, extending converter lifetime and eliminating need for redundant MOV-based protection.

Use Scenario: Secondary-level ESD protection on RS-485 transceiver VCC and DE/RE pins in building management systems.

IC Role / Device Role / Timing Role: Low-leakage TVS placed adjacent to transceiver pins to handle ±8 kV contact discharge per IEC 61000-4-2.

Use Value: Limits transient-induced latch-up risk with <1 μA leakage at 28.2 V, ensuring reliable bus arbitration during field maintenance events.

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
SMBJ28A (Bourns)	Same DO-214AA (SMB) package; 28 V V_WM, 45.4 V V_C @ 8.8 A, but rated for 600 W peak power.	Higher power rating suits higher-energy transients; SMB footprint requires PCB layout change vs. DO-41.	Select SMBJ28A only if surge energy exceeds 400 W or surface-mount assembly is mandated.
P6KE27A (ON Semiconductor)	DO-15 package; 27 V V_WM, 43.5 V V_C @ 9.2 A, 600 W rating; slightly lower V_WM and tighter V_BR tolerance.	Lower stand-off voltage may trigger prematurely in 28 V nominal systems; legacy part with longer lead times.	Prefer BZW04-28 for precise 28.2 V hold-off and AEC-Q101-ready variants (BZW04-28H) in new designs.

Compared with SMBJ28A and P6KE27A, BZW04-28 offers optimal balance of 28.2 V stand-off accuracy, DO-41 through-hole compatibility, and 400 W surge capacity - making it ideal for cost-sensitive, thermally constrained, or manually assembled 24 V industrial and automotive subsystems where exact voltage margin is critical.

Availability

BZW04-28 is available at Aetrix Electronics and suitable for automotive lighting control, industrial PLC I/O protection, and DC power supply input stage applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for BZW04-28 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in discrete power devices, TVS diodes, rectifiers, and thyristors for industrial and automotive markets.

The BZW04 series was developed to deliver high-reliability, high-power transient suppression in compact DO-41 packages - targeting cost-effective, thermally robust protection for 12 V and 24 V systems where AEC-Q101 qualification and tight V_WM tolerance are essential.

FAQ

What is the maximum clamping voltage of BZW04-28 under standard surge conditions?

The BZW04-28 has a maximum clamping voltage (V_C) of 45.7 V when subjected to an 8.8 A peak pulse current with a 10/1000 μs waveform. This value is measured per ANSI/IEEE C62.35 and represents the highest voltage the device allows across its terminals during surge conduction - critical for ensuring protected ICs remain within their absolute maximum ratings. The BZW04-28 maintains this performance consistently across its qualified operating temperature range.

Is BZW04-28 suitable for automotive applications requiring AEC-Q101 qualification?

The base BZW04-28 is not AEC-Q101 qualified; however, the variant BZW04-28H is explicitly certified to AEC-Q101. Both share identical electrical parameters including V_WM = 28.2 V, V_BR = 31.4–34.7 V, and V_C = 45.7 V. For automotive use, specify BZW04-28H to ensure compliance with stress testing requirements for temperature cycling, humidity, and mechanical shock - while retaining full compatibility with BZW04-28's design-in and layout.

What is the reverse leakage current specification for BZW04-28 at its working stand-off voltage?

At its working stand-off voltage (V_WM) of 28.2 V, the BZW04-28 exhibits a maximum reverse leakage current (I_R) of 1 μA at 25°C ambient temperature. This ultra-low leakage ensures minimal power loss in always-on circuits and avoids false triggering in high-impedance sensing nodes. The BZW04-28 maintains this specification across its full operating junction temperature range of –55°C to +175°C.

How does the thermal performance of BZW04-28 affect PCB layout decisions?

The BZW04-28 has a junction-to-ambient thermal resistance (R_θJA) of 100°C/W when mounted on a PCB with 10 mm lead lengths. To avoid exceeding its 175°C maximum junction temperature during repeated surges, designers must limit average power dissipation and provide adequate copper pour area around leads. The BZW04-28's DO-41 package supports both wave and reflow soldering, but thermal relief pads should be minimized to maintain heat transfer efficiency.

Can BZW04-28 be used in bidirectional configurations?

No - BZW04-28 is a unidirectional TVS diode, marked with a cathode band and intended for DC line-to-ground protection. For bidirectional AC or differential signal protection, the designated variant is BZW04-28B, which has symmetrical breakdown characteristics and no polarity marking. Using BZW04-28 in bidirectional applications risks failure during negative transients, as it lacks reverse conduction capability. Always match the BZW04-28 part number to unidirectional use cases only.

BZW04-28 Specifications

Product attributes: Attribute value

Manufacturer:: Taiwan Semiconductor Corporation

Package/Case:: DO-204AL, DO-41, Axial

Series:: BZW04

Packaging:: Tape & Reel (TR)

Product Status:: Active

Type:: Zener

Unidirectional Channels:: 1

Bidirectional Channels:: -

Voltage - Reverse Standoff (Typ):: 28.2V

Voltage - Breakdown (Min):: 31.4V

Voltage - Clamping (Max) @ Ipp:: 45.7V

Current - Peak Pulse (10/1000µs):: 8.8A

Power - Peak Pulse:: 400W

Power Line Protection:: No

Applications:: General Purpose

Capacitance @ Frequency:: -

Operating Temperature:: -55°C ~ 175°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-204AL (DO-41)

BZW04-28 FAQ

1.How can I place an order for BZW04-28 through Aetrix?

Please submit a Request for Quotation (RFQ) for BZW04-28 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for BZW04-28 reliable?

The price and inventory of BZW04-28 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZW04-28 is usually 5 days.

3.What payment methods are accepted for BZW04-28?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZW04-28 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for BZW04-28?

BZW04-28 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your BZW04-28 order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for BZW04-28?

For technical support, including BZW04-28 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZW04-28 requirements.

6.How does Aetrix verify that BZW04-28 is sourced from the original manufacturer or authorized distributors?

All BZW04-28 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BZW04-28 meets industry standards.

7.What is the process for return or replacement of BZW04-28?

All BZW04-28 units undergo pre-shipment inspection (PSI). If there is an issue with BZW04-28, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The BZW04-28 part is unused and in its original packaging.

Return procedure for BZW04-28:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…